反离子对全氟辛酸盐与高聚物的相互作用的影响

Effect of Counterions on the Interactions between Perfluorooctanoate and Polymers

通过表面张力和电导率测定,研究了全氟辛酸铵/四烷基铵(C7F15COON(CnH2n+1)4,n=0,1,2,3,4)与聚氧乙烯(PEO,分子量20000)和聚氧乙烯聚氧丙烯三嵌段共聚物(Pluronic F68)的相互作用.结果表明,对PEO-C7F15COON(CnH2n+1)4混合体系,只有全氟辛酸铵、全氟辛酸四甲铵与PEO之间有明显的相互作用.对F68-C7F15COON(CnH2n+1)4混合体系,只有全氟辛酸四丁铵未发现与F68有明显的相互作用.说明全氟辛酸盐的反离子越大,其与高聚物间的相互作用越弱.增加高聚物的疏水性可以增强表面活性剂与高聚物的相互作用.

The interactions of ammonium/tetraalkylammonium perfluorooctanoate（C7F15COON（CnH2n＋1）4, n=0, 1, 2, 3, 4） with polyethylene oxide（PEO, Mw=20000） and block copolymer（Pluronic F68） were investigated by surface tension and electrical conductivity measurements.It shows that the perfluorooctanoates exhibit significant interactions with PEO only when the counterions are ammonium and tetramethylammo-nium.However, for F68-C7F15COON（CnH2n＋1）4 mixtures, only tetrabutylammonium perfluorooctanoate shows no significant interaction with F68.It is concluded that the interactions between fluorinated surfactants and the polymers decrease with the increase of the counterion size, but increase with the increase of the hydrophobicity of polymers.